Oenothera pilosella (Prairie Sundrops)(Long-tongued bees suck nectar and/or collect pollen; short-tongued
bees collect pollen and they are mostly non-pollinating; flies and beetles feed on
pollen and they are non-pollinating; other insects suck nectar. This plant was
originally described as Oenothera fruticosa by Charles Robertson, but he
was probably referring to Oenothera pilosella. Observations are from Robertson, Moure & Hurd, and Wilhelm & Rericha as indicated below.)